Electric connector for boards, method of molding electrical connector housing for board, and metal mold for injection molding of electrical connector housing

ABSTRACT

The housing  3  made of an insulating synthetic resin has a connecting recess  13  opened in the connecting direction Y. The side walls  14  defining the connecting recess  13  is provided with terminal retainer recesses  18  arranged side by side in the lateral direction X. The openings  25  are formed in the portion of the outer side surface of each side wall  14  which correspond to the partition walls  26  separating adjacent terminal retainer recesses  18  from each other. The openings  25  have the terminal retainer holes  18 , which are formed on both sides of the corresponding partition walls  26 , opened to the exterior thereof. When the housing  3  is molded, the pins for forming the openings  25  are interposed among the ribs of the metal mold which are used to form the adjacent terminal retainer recesses  18 , the deformation of the ribs being thereby held down.

TECHNICAL FIELD

This invention relates to an electric-connector for boards, fixed to asurface of a circuit board.

BACKGROUND ART

In recent years, the spread of personal computers has been remarkable.In a personal computer, a pair of electric connectors used for theboard-to-board connection, and a pair of electric connectors used forthe wire-to-board connection are provided.

For example, an electric connector fixed to an outer surface of a powerboard which controls a power source and an electric connector fixed to amother board on which a CPU is mounted are connected together. Oneelectric connector is a plug type connector having a connectingprojection, while the other electric connector is a receptacle typeconnector having a connecting recess.

Conventionally, as a receptacle type electric connector of this kind (asdisclosed in, for example, JP-A-11-067364), an electric connector havingterminal retainer recesses opened in the connector-joining direction andformed in each of a pair of side walls which define a connecting recesshas heretofore been provided.

With demands for the miniaturization and a higher function of a personalcomputer body, the electric connector of this kind has also demanded theminiaturization thereof and an increase in the number of electrodesthereof.

In general, the depth of the terminal retainer recesses between theelectric connectors of this kind is set to 12 to 13 mm. In the meantime,it is demanded that the width of each of the terminal retainer recessesbe set to, for example, around 0.4 mm, and that the intervals (pitch) atwhich the terminal retainer recesses are arranged be set to, forexample, around 0.6 mm. In this electric connector, it is necessary thatthe thickness of each partition wall between adjacent terminal retainerrecesses be set to, for example, as extremely small as 0.1 mm.

Therefore, in order to meet these demands in the connector disclosed inthe above-mentioned JP-A-11-067364, the following new problems arise.

In a metal mold for molding a housing, it is necessary that terminalretaining recess-molding ribs be made thin (for example, 0.4 mm), andthat the intervals of the ribs be set small (for example, 0.6 mm).However, when the terminal retainer recess-forming ribs are thus formed,there is a fear of deforming the ribs due to the pressure occurringduring an injection molding operation. When the ribs are deformed duringan injection molding operation, the thin partition walls (having athickness of, for example, 0.1 mm) between the terminal retainerrecesses are also deformed. In addition, the position accuracy of theterminal retainer recesses is deteriorated, and in its turn the positionaccuracy of the terminals decreases. As a result, the reliability of theelectrical connection of the connectors lowers.

DISCLOSURE OF THE INVENTION

The present invention has been made in view of these problems, and aimsat providing a miniaturized, highly reliable, electric connector forboards, capable of heightening the position accuracy of the terminalsarranged at small intervals.

In order to attain this object, the present invention provides anelectric connector for boards, including a housing of an insulatingsynthetic resin having a connecting recess opened in the connectingdirection, and a plurality of terminals retained side by side by thehousing, the housing including a pair of opposed side walls extendinglaterally so as to define the connecting recess therebetween, terminalretainer recesses penetrating through the respective side walls in theconnecting direction, partition walls provided between adjacent terminalretainer recesses, and a plurality of openings formed in the portions ofeach of the partition walls, each opening corresponds to each partitionwall, each opening making open to the exterior a pair of terminalretainer recesses opposed to each other via the partition wall opposedto the corresponding opening.

According to the present invention, pins for forming the openings in theouter side surface of the partition walls when the housing is injectionmolded in a metal mold are interposed between the adjacent terminalretainer recess-forming ribs in the metal mold. Therefore, during theinjection molding operation, the deformation of the terminal retainerrecess-forming ribs is held down, so that the position accuracy of theterminal retainer recesses (i.e. partition walls) arranged at smallregular intervals can be heightened. In its return, a miniaturized,highly reliable, electric connector having a high position accuracy ofthe terminals can be provided.

It is preferable that the openings in the outer side surface of thesidewall be provided generally in an intermediate portion in thedirection of the height of the side wall for the purpose of reliablysuppressing the deformation of the terminal retainer recess-forming ribsduring the injection molding operation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a plan view of the electric connector of a mode of embodimentof the present invention, and FIG. 1B a side view thereof;

FIG. 2 is a sectional view taken along the line II-II in FIG. 1B;

FIG. 3 is a sectional view taken along the line III-III in FIG. 1B;

FIG. 4 is a schematic sectional view of the electric connector connectedto an opposed plug type electric connector;

FIG. 5 is a partially cutaway view in enlarged perspective of a sidewall of the electric connector; and

FIG. 6 is a schematic perspective view showing the construction of ametal mold.

Note that in the drawings, 1 denotes a (receptacle type) electricconnector (electric connector for boards), 2 a circuit board, 2 a anouter surface, 3 a housing, 3 a a counter-surface, 4 and 5 terminals(for signals), 6 terminals (for a power source), 11 (plug type) electricconnector, 12 a connecting projection, 13 a connecting recess, 14 and 15side walls, 14 a and 15 a connecting-side end surfaces, 14 b and 15 bouter surfaces, 18 terminal retainer recesses, 19 a main body portion,20 an elastically bent portion, 21 a projecting portion, 22 a contact,23 a contact end portion, 25 openings, 26 partition walls, 30 a metalmold, 31 opening-forming pins, 32 terminal retainer recess-forming ribs,40 opened portions, X a lateral direction, Y a connecting direction (adirection of the height), and Z a direction opposite to (the connectingdirection).

BEST MODE FOR CARRYING OUT THE INVENTION

A preferred mode of embodiment of the present invention will now bedescribed with reference to the attached drawings.

FIG. 1A and FIG. 1B are plan view and a side view of a mode ofembodiment of the electric connector for boards according to the presentinvention, FIG. 2 a sectional view taken along the line II-II in FIG.1B, and FIG. 3 a sectional view taken along the line III-III in FIG. 1B.

This electric connector 1 is a receptacle type electric connector. Thismode of embodiment will be described on the basis of a case where theelectric connector is used as one of a pair of board-to-board connectingelectric connectors as shown in FIG. 4. This electric connector 1 canalso be used as one of a pair of wire-to-board connecting electricconnectors.

Referring to FIG. 2, the electric connector 1 is provided with a housing3 fixed to a surface 2 a of a circuit board 2 and made of an insulatingsynthetic resin, and a plurality of terminals for signals 4, 5 arrangedin two lateral rows so that the terminals 4, 5 penetrate through thehousing 3. Referring to FIG. 3, the electric connector 1 is providedwith terminals 6 for a power source, arranged in two lateral rows sothat the terminals 6 extend through the housing 3.

Referring to FIG. 1A and FIG. 1B, the housing 3 is long in the lateraldirection X. Referring to FIG. 1B, the housing 3 has a counter-surface 3a opposed to the surface 2 a of the circuit board 2 when the housing isfixed to the circuit board 2. The end portions opposed to each other inthe lateral direction X of this counter-surface 3 a are formed as a pairof fixing portions 7, 7 to be fixed to the surface 2 a of the circuitboard 2.

On the counter-surface 3 a, an intermediate portion 8 between the twofixing portions 7, 7 is in a position offset upward from the fixingportions 7, and a clearance of a predetermined height is providedbetween the intermediate portion 8 and the surface 2 a of the circuitboard 2. Referring to FIG. 1A and FIG. B and FIG. 2, the leads 4 a, 5 aof the terminals 4, 5 project from the intermediate portion 8, extendsideways, and are soldered (not shown) to the surface 2 a of the circuitboard 2.

In the meantime, the leads 6 a of the terminals 6 are held in thecorresponding terminal retainer recesses 50 as shown in FIG. 3. As shownin FIG. 1A and FIG. 1B and FIG. 3, the leads 6 a of the terminals 6extend outward from side holes of the fixing portions 7, 7, and aresoldered to conductive portions of the surface 2 a of the circuit board2.

As shown in FIG. 1B, a pair of locking members 9, 10 formed out of asynthetic resin integral with the housing 3 project in a boss-like statefrom the two fixing portions 7, 7. The locking members 9, 10 extendthrough corresponding locking recesses 2 b, 2 c in the circuit board 2and locked therein as shown in FIG. 2 or FIG. 3. Each of the lockingmembers 9, 10 are formed, for example, so as to have different diameterportions for thereby preventing the locking members from being fixedreversely to the circuit board 2.

Referring to FIG. 1A and FIG. 1B, the electric connector 1 is of aso-called top type, and the housing 3 thereof has the connecting recess13 for inserting therein and connected thereto the connecting projection12 of the plug type electric connector 11 shown in FIG. 4 and pairedwith the connector 1. The connecting recess 13 is opened in theconnecting direction Y of the electric connector 1. The plug typeelectric connector 11 is of a so-called side type fixed to the opposedcircuit board 60, and extending at its connecting projection 12 inparallel with the circuit board 60. However, the plug type electricconnector 11 may also be of a so-called top type. Referring to FIG. 4,to the terminal 5 in a connected state, the terminal 70 opposed theretoof the plug type electric connector 11 is connected.

Referring to FIG. 1A, the connecting recess 12 is defined by a pair ofopposed side walls 14, 15 and a pair of opposed end walls 16, 17, all ofwhich are provided in the housing 3, and has a rectangular shape.

Referring to FIG. 2, each of the side walls 14, 15 is provided with aplurality of terminal retainer recesses 18 arranged side by side (in thelateral direction X in FIG. 1) and penetrating through the side walls14, 15 in the connecting direction Y.

The terminal retainer recesses 18 are opened in the connecting side endsurfaces 14 a, 15 a, and extend in the direction Z contrary to theconnecting direction Y, the retainer recesses 18 being thereby opened inthe above-mentioned counter surface 3 a as well.

Referring to FIG. 2, the terminal 4 is provided with an elongated mainbody 19 press-fitted and locked in a terminal retainer recess 18, aprojecting portion 21 extending from an upper end of the main body 19via an S-shaped elastically bent portion 20 in the connecting directionY, a contact 22 made of a mountain-shaped projection formed in theprojecting portion 21, a contact end portion 23 extending diagonallyfrom the contact 22, and a lead 4 a extending outward in a bent statefrom a lower end of the main body 19.

The terminal retainer recess 18 is opened to the connecting recess 13through the opened portion 40. Since the projecting portion 21 iselastically urged toward the connecting recess 13 by the elasticallybent portion 20, the contact 22 enters the interior of the connectingrecess 13 through the opened portion 40. Since the contact end portion23 engages a stopper 24 provided on an end portion of the correspondingside wall 14, the quantity of projection of the contact 22 toward theconnecting recess 13 is restricted.

As shown in FIG. 4, the terminal 5 also has the same construction as theterminal 4.

Referring to FIG. 1B and FIG. 2, the outer side surfaces 14 b, 15 b ofthe side walls 14, 15, a plurality of vertically long openings 25 areformed side by side (in a row in the lateral direction X). The opening25 is provided generally in an intermediate portion in the direction ofthe height (i.e. in the connecting direction Y) of each of the sidewalls 14, 15.

The side wall 14 and the side wall 15 have the same construction. Theside wall 14 has partition walls 26 separating the adjacent terminalretainer recesses 18 from each other. The openings 25 are formed in theouter side surface 14 b of the side wall, and the openings 25 areopposed to the relative partition walls 26. Further, the openings 25 areformed by cutting out the parts of the side wall. The openingcommunicates with the terminal retainer recesses 18 on both sides via apair of communication portions 25 a (in FIG. 5, one communicationportion 25 a only is shown). As a result, each opening 25 makes a pairof terminal retainer recesses 18, 18 open to the exterior of the housing3 respectively, wherein the pair of terminal retainer recesses 18, 18are opposed to each other via the partition walls 26 opposed to theopening 25.

FIG. 6 is a schematic drawing showing the part of a metal mold which isused to injection mold the portion shown in FIG. 5 of the housing 3. Inthe metal mold 30, pins 31 for forming the openings 25 are interposedamong the ribs 32 of the metal mold 30 for forming the adjacent terminalretainer recesses during an injection molding operation. Therefore, thedeformation of the ribs 32 for forming the terminal retainer holesduring an injection molding operation is held down. This enables theposition accuracy of the terminal retainer recesses 18 arranged at smallintervals and partition walls 26 to be heightened, and in its turn theposition accuracy of the terminals 4, 5 to be also heightened. Thus, aminiaturized, highly reliable, electric connector 1 can be provided.

Especially, since the openings 25 are provided in the portions of theside walls 14, 15 which generally correspond to intermediate sections inthe direction of the height (i.e. in the connecting direction Y) of eachof the side wall 14, 15, the deformation of the ribs 32 for forming theterminal retainer holes during an injection molding operation can bereliably prevented.

The present invention is not limited to the above-described mode ofembodiment but can be modified variously within the scope thereof.

INDUSTRIAL APPLICABILITY:

When the housing is injection molded in the metal mold in the presentinvention, the pins for forming the openings in the outer side surfaceof the partition walls come to be interposed among the ribs of the metalmold for forming the adjacent terminal retainer recesses. Therefore,since the deformation of the terminal retainer recess-forming ribs canbe held down during an injection molding operation, the positionaccuracy of the terminal retainer recesses (partition walls) arranged atsmall intervals can be heightened, and in its turn the position accuracyof the terminals can also be heightened. This enables a miniaturized,highly reliable, electric connector to be provided.

1. An electric connector for boards, comprising: a housing, made of aninsulating synthetic resin, including a connecting recess opened in aconnecting direction; and plural terminals retained laterally arrangedin the housing, wherein the housing further includes: a pair of opposedside walls extending laterally so as to define a connecting recesstherebetween, plural terminal retainer recesses penetrating throughrespective side walls in the connecting direction, plural partitionwalls for separating the adjacent terminal retainer recesses from eachother, and plural openings formed in outer side surfaces of respectiveside walls, corresponding to respective partition walls, wherein,through each the opening, a pair of the terminal retainer recessesadjacent each other via one of the partition walls corresponding to theopening are opened to the exterior of housing.
 2. The electric connectorfor boards according to claim 1, wherein the openings of the outer sidesurfaces of the side walls are arranged substantially in the verticallyintermediate portions of the side walls.
 3. A metal mold of injectionmolding, for forming a housing of an electric connector for boards,wherein the housing has plural terminal retainer recesses penetratingthrough the housing in a connecting direction, comprising: pluralterminal retainer recess-forming ribs for forming the plural terminalretainer recesses; and plural opening-forming pins, each interposingbetween a pair of adjacent terminal retainer recess-forming ribs, forforming openings in a side wall of the housing.
 4. The metal mold ofinjection molding according to claim 3, wherein the opening-forming pinsare arranged substantially at the vertically intermediate portions ofthe side walls of the housing.
 5. A method of forming a housing of anelectric connector for boards, wherein the housing has plural terminalrecesses penetrating through the housing in the connecting direction,comprising: injecting synthetic resin to a metal mold, wherein the metalmold comprises plural terminal retainer recess-forming ribs for formingthe plural terminal retainer recesses, and opening-forming pins, eachinterposing between a pair of adjacent terminal retainer recess-formingribs, for forming openings in a side wall of the housing.